Answer:
Visitacion de la Torre's distribution "Tourist spots of Manila, 1571-1930" is classified as an optional source.
An essential source relates to an underlying or firsthand story of an occasion or period, like diaries, correspondences, pictures, and official records. On the other hand, de la Torre's distribution is viewed as an optional source since it presents data about an occasion or time that is gotten from the review and assessment of essential sources or other optional sources. The premise of de la Torre's work is the exploration and examination of essential sources concerning Manila's tourist spots from 1571-1930.